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Back in 2007 I wrote three posts about Continuous Packet Connectivity (CPC), a bundle of 3GPP features aimed at improving network interactions for applications on 3G HSPA devices that only require a low bitrate or only poll the network periodically (e.g. once every few minutes).For details see here, here and here. All these features were part of 3GPP Release 7. One important feature was missing though, and that was to improve uplink speeds and reaction time in more power efficient states. This feature was added in 3GPP Release 8 in the "Enhanced Uplink for CELL_FACH State" Work Item. For details see RP-070677.

And here is what the feature actually does:

Today, when a HSPA mobile device is not in the Cell-DCH state, i.e. it is not observing and receiving data over the High Speed Shared Channels, but is instead in the less power consuming Cell-FACH, Cell-PCH or URA-PCH states, uplink packets are sent over the Random Access Channel (RACH). While this works quite o.k. there are several shortcomings:

• The capacity of the RACH is very limited. Hence, when the network detects that a device uses this channel for more than just a small IP packet or two, the connection  is immediately transferred to the fully active state (Cell-DCH). That requires a lot of signaling and in case the mobile ceases transmission again afterward, e.g. because it only wanted to send a keep-alive or poll message, it wastes capacity in the cell.

• State transitions from Cell-FACH to Cell-DCH take some time, in the order of hundreds of milliseconds, so it has a negative impact on user experience.

• As capacity on the RACH is very limited, only few users can use it at a time.

• Round trip delay times due to the use of the RACH are in the order of 250 to 300 ms compared to far less than 80 ms in fully active state.

• Only very small data packets can be transferred in on RACH slot. The document linked above contains an analysis that comes to the conclusion that an IP packet with 500 bytes requires over 10 RACH transmissions.

O.k., so what is the solution!? Instead of the RACH, Release 8 has specified how to use a fast Enhanced Uplink Channel (E-DCH) that was originally specified for HSUPA. This E-DCH is configured with default values, i.e. a modulation and coding scheme that is conservative enough so even devices at the edge of a cell can use it. No power control and channel quality feedback is necessary. Access to the channel is controlled by the network with the Acquisition Indication Channel (AICH) as before.

Looks like a very worthwhile feature to me, let's see when it appears in practice.

I really really really like my netbook, it is so convenient, especially when traveling and not having a lot of space. But one of the things that is missing is screen real estate, especially on the vertical. My Ubuntu and the Gnome GUI make good use of what's available as the icons and window frames are smaller than on MS Windows. But even with MS Windows, working with a netbook should be o.k. But what about Microsoft Office that uses a ribbon interface instead of the traditional menu / icons on top of the window? The height of the ribbons costs precious vertical space and as far as I know there's no way to change that!? So I wonder if Microsoft at some point will come with a netbook / small screen optimized UI for its Office suite!?

What about you, how do you feel about 'ribbons' on smaller screens?

I've done a couple of looking back a bit into the past posts recently so it's time again to look a bit into the future. Today we are at 3GPP Release 10 in standardization and when I look back to Release 99 or even further, we've come a long way. So, will I or 3GPP still be around for 3GPP Release 20? With a release cycle of about 18 months, that should be in 15 years from now. I wonder how wireless networks will look then!? Will there be a similar difference compared to Release 10 to GSM Release 97? That's difficult to imagine. But then, who back then working on Release 97 could have imagined HSPA+ or LTE?

With the digital dividend band in Germany about the be auctioned in April this year, it's interesting to see under which conditions spectrum spectrum will be sold to the highest bidders. As the 800 MHz band is ideal to bring high speed Internet to undeserved rural areas, the auction conditions set by the "Bundesnetzagentur" contains the following conditions:

By 2016, 90% of the population of cities and areas selected by regional governments (Bundesländer) must be either served by high speed wireless or wireline Internet access. Small villages will get precedence over larger towns by grouping them into 4 priorities:

• Priority 1: Areas and villages with a population less than 5.000 inhabitants
• Priority 2: Towns and areas with a population up to 20.000 inhabitants
• Priority 3: Cities up to 50.000 inhabitants (are there any such cities in Germany left that don't have 3G or DSL coverage yet???)
• Priority 4: Beyond that, anything goes

Priority 2 towns can only be served once at least 90% of the priority 1 areas are covered, and so on.

For more details, click on the link above for 181 pages of nitty gritty details.

And another interesting chart from Telecom Austria's recent annual financial report. Page 31 shows how over the past years, fixed an mobile network operators in Europe have started to re-integrate again to leverage their fixed and mobile assets for combined offers to customers and to benefit from a common network. One of the few places where the trend has not stuck is the UK. Bad luck for BT in my eyes who was just a bit too quick to sell off their mobile business at the time.

It's still early days though and I haven't seen a lot of products coming out of such re-integrations yet. But let's see, maybe in two or three years there will be a chart that shows in which countries combined offers beyond a single invoice are on the market.

France is one of the countries in Europe where the 900 MHz band has been opened up for technologies other than GSM and where a 3G network operator has started deploying UMTS 900. Some UMTS 900 / 2100 MHz USB sticks have been available for a while and especially Nokia puts UMTS 900 MHz into a number of its higher end devices in addition to the standard 2100 MHz band support. Here's a link to the coverage map of Orange France that shows which areas are covered with the standard 2100 MHz UMTS band and which are covered with UMTS 900.

It's interesting to compare those maps with satellite maps to see what kind of areas are covered with UMTS 900. It's very rural areas indeed so it looks like Orange sees a business case for covering such sparsely populated areas with a frequency band on which the signal can travel much farther than on 2.1 GHz. Also, it proves my assumption that especially in rural areas, there is enough bandwidth available to run both GSM and UMTS alongside each other, have enough bandwidth for GSM voice and data and still enough space between the technologies to keep the interference between the technologies on the air interface in check.

Following up from an earlier post on multitasking I thought about how a perfect phone for me would look like. Admitting that I am difficult to please and that there is no single best phone for everyone, here's what I need in my next phone:

Taking the Nokia N95 as a baseline it has many of the things I need:

• A multitasking operating system so the device can really be 'the world in my hand' as Nokia once said.
• A good camera
• Lots of memory for programs to execute
• Lots of flash memory
• A big but not too big screen, it must fit in the pocket
• Wi-Fi
• A VoIP client
• GPS & a good navigation software I can also use offline because I travel a lot and data roaming costs are sometimes prohibitive
• A reliable alarm clock
• An e-mail client with partial e-mail  download
• There must be an Opera Mini version for my future device. Absolutely essential!
• SMS and video calling should be perfectly polished and implemented
• Robustness: It should survive falling to the floor every now and then

O.k. that's what I already have, let's see what I'd like to have in addition:

An easy to use App Store, one who's whole mission is to aggregate the most popular applications at a central place and that gives gives developers a chance to make money. What I don't want is an App Store who is designed to lock me into the preferences of a single company that decides for me which applications I am allowed to use and which not.

When I buy a device, it's mine and I want to do with it what I want without anyone telling me otherwise. In practice that means that I can download applications also from other web sites, receive them via e-mail or side-load them via a memory card. That's how I do it on my PC and I see no reason why it should be different on my mobile device.

Ah yes, I want a memory card so I can load stuff onto my device the way I want. In no way do I want to be limited to a single PC program to exchange content with my device. After all, it's my device and I want to load anything onto it I want.

Privacy is very important to me so I want a device that is designed to give me as much privacy as possible. Some hints: Anonymous interaction with the application store to download applications that are free. A way to buy applications from the app store anonymously. Synchronization of my calendar and address book but not on a single server on the net controlled by a big company but at home so I am in control and nobody by accident or design can reign over my data.

I want a nice graphical user interface and I want a touchscreen, and one that works. You know, a touch screen your fingers glide over nicely, without too much resistance and applications that understand two finger input to zoom in, zoom out, rotate, etc. I am still sort of keen on a physical keyboard but o.k. that's negotiable.

And finally, the device should be slim and lightweight.

A real challenge I admit and no device on the market currently fulfills all points. But as I said I am hard to please and a device which misses even only a single one raises serious doubts in me if it is the next device for me. How long will I have to wait before something shows up that is a worthy successor to the N95?

Last evening, when traveling home by train, I downloaded a 6 MB PDF specification document over HSPA and was actually surprised it took longer than just a couple of seconds. The download speed was roughly about 2 MBit/s. Strange I wondered, why is the network so "slow" tonight? Turns out it wasn't the HSPA network that was "slow", it was the server on the other end that couldn't deliver the document faster. Even over my 25 MBit/s VDSL line at home, the document wouldn't load faster. So I wondered, since when do I percieve a download rate of 2 MBit/s as slow? And secondly, it seems this was the first time I consciously realized that a server on the network could not fill up the bandwidth available I had on the wireless network.

Here's an interesting number from Telecom Austria's annual report (page here, pdf here) on page 53: Total mobile communications revenue was 3.2 billion Euros for 2009. Out of that, 136.5 million Euros came from roaming charges.

via heise.de

Once upon a time, when business people traveled abroad, they were probably highly lucrative for mobile network operators because they were less afraid to use their mobile phone abroad for making phone calls back to their home country compared to ordinary users who would get a regular invoice every month to pay on their own.

These days, most business travelers carry a Blackberry or similar device to receive their e-mail while on the move. I guess that few of them disable the feature while abroad and just use the device just for making voice calls.

On the one hand it seems like a good opportunity for mobile network operators for additional revenues as data roaming is still quite costly to say the least. So that's a good thing, no? On the other hand, however, I wonder how many voice calls abroad are replaced by the e-mail capability and if the extra data roaming revenue actually compensates for it!?

So you business travelers out there reading this blog, how many voice calls abroad are replaced by your Blackberrie's e-mail capabilities?